Although on the disabled list at the moment, Alfonzo was batting .328 over his last 20 contests, while Vizquel has been stunning at the plate on the club's road trip, boasting a five-hit game at Minnesota.

Matheny is surprisingly among the top offensive catching leaders in the league with six homers and 30 RBIs in 54 games, while Snow has revived his game after injuries, sickness and a mild slump.

Following a slow start, Durham has hit over .300 in the past 40 contests.

San Francisco fans can cast their votes up to 25 times with the Ameriquest All-Star Online Ballot at sfgiants.com. Online balloting ends at 8:59 p.m. PT on June 30.

From July 3-6, fans can again participate in the Ameriquest All-Star Final Vote, which determines the final position player for each League's 32-man roster.

Rich Draper is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.